AC Big 10 runs but hard to start

May 20, 2014

I rebuilt the carb on my big 10. When I put it back together after cleaning and some new parts, I opened both jets 1 1/4 turns from closed, as a starting point.

I put it on and got it running fine, but it is very hard to start. I have the air cleaner off and I like to choke it with my hand. I can often get it to fire a few times when choking, but it doesn't take off.

I do this a few more times and I've flooded it- gas dipping from the bottom of the carb.

I didn't end up using the new diagonal brass tube from the kit- it was a bit shorter, and the old one looked fine. I don't what I could have done wrong here.

I wonder if these carbs are notorious for flooding or have any chronic issues?

May 20, 2014

I have seen these carbs flood and drip. I installed a fuel shutoff valve so I could turn the fuel off while cranking so it would not flood. Once I got the fuel to stop flowing, the tractor would start and I would turn the fuel back on.Are you sure the choke plate is closing all the way?

You may have to bend the tab on the float down a bit so the bowl does not overfill.

Best of luck.

May 21, 2014

Set the idle valve at 1/2 to 3/4 turns instead of 1-1/4 turns and try that.

May 22, 2014

quote:Originally posted by RayS

Set the idle valve at 1/2 to 3/4 turns instead of 1-1/4 turns and try that.

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id="quote">Thanks SO MUCH for taking the time to post this! I'll try it and report back.Lynn Kasdorf

May 22, 2014

Hold the throttle closed at the carb.while cranking.

I have 2 b-10 i have to do this with.

Good Luck!

May 22, 2014

Willy has a good point. I too have to hold the throttle closed while starting my b 10

May 22, 2014

It's also possible that one or both gasket that sandwiches the throttle wire and baffle are out of place. With the engine running, spray some carb cleaner of brake cleaner around the joints of intake elbow and see if the engine reacts to it.